Aljustable condenser



Jan. 15, 1929.

R. A. PFLEGER ADJUSTABLE CONDENSER Filed Feb. '7, 1927 A T TORNEK Patented Jan. 15, 1929.

UNITED STATES ROBERT A. PFLEGER, 013 LOS ANGELES, CALIFORNIA.

ADJUSTABLE CONDENSER.

Application filed February 7, 1927. Serial No. 166,428.

My invention relates to radio equipment, and particularly to a novel electric condenser which is quite useful in radio apparatus.

It is desirable to have all of the condensers of a radio set of the same capacity, and this is conveniently done by adjusting the size of the spaces between the condenser plates.

It is an object of this invention to provide a condenser in which the spaces between the plates may be readily adusted.

It is an object of this invention to provide a condenser in which the spaces between the plates may be readily adjusted after the condenser has been installed in a set and without changing the setting of the dial.

It is a still further object of this invention to provide in a condenser of the character described, an adjustment screw by which a very fine adjustment may be procured.

Other objects and advantages of my invention will be made manifest in the following description.

Referring to the drawing in which I illustrate a preferred form of my invention,

Fig. 1 is a Vertical cross section Fig. 2 is a section taken on the line 2-2 of Fi 1.

I teferring to the drawing in detail, 11 represents a panel to which a bracket 12 is secured by a screw 13 and other suitable means. A base 14 is secured to the lower end of the bracket 12 by means of a screw' 15, the base 14 extending horizontally inward from the bracket. An opening 17 is formed vertically through the base 14, this opening 17 bein elongated in the direction of the length 0 the base 14. Supported by the base 14 is a block 19 having a depending portion 20 which extends into the opening 17. The depending portion 20 is substantially the same width as the opening 17 but is shorter so that the block may move longitudinally in the opening. The upper part of the block 19 isprovided in the form of a flange 21 which rests on the upper face of the base 14. Formedin the lower part of the block 14 and connected to the lower part of the opening 17 is a recess 23 having a slightly arcuated face 24. Placed in the recess 23 is a spring retaining plate 25 which is secured to the lower part of the depending portion 20 of the block 19 by means of screws 26. The retaining plate 25 is flexed so that it is arcuated in congruency with the face 24 of the recess 23. The purpose of this arrangement is to hold the block 19 firmly in the opening 17 but allow it to move longitudinally therein. The block 19 is moved longitudinally in the opening 17 by means of a differential screw 29. The difierential screw 29 has a large threaded portion 30 which is adapted to be screwed into a threaded opening 31 formed in the right end of the base 14 in Fig. 1. Projected from the large threaded portion 31 is a small threaded portion 32 which is adapted .to screw into a threaded cavity 33. The differential screw 29 is rotated by application of a suitable wrench to a head 35 thereof. The operation is as follows: When the differential screw 29 is rotated in an anti-clockwise direction the coarse threaded portion 30 moves to the right in the threaded opening 31. The fine threaded portion 32 also moves to the right relative to the block 19 which, of course, means that the block 19 moves to the left relative to the differential screw 29. The resultant movement of the block 19 to the right is equal to the difference between the movement of the differential screw 29 to the right and the movement of the differential screw relative to the block 19. By this arrangement it is possible. to obtain a very fine adjustment without any complicated means.

The block 19 forms a part of the stator of the condenser. The block 19 supports a series of relatively spaced stator plates 37 which are adatped to cooperate with rotor plates 38 which are carried by a spindle 39. The rotor plates 38 are relatively spaced and project downward between the stator plates 37. The spindle 39 and the rotor plates 38 form a part of the rotor of the condenser.

The spindle 39 has an opening formed therethrough through which a shaft 61 is extended. The spindle and shaft are secured together by means of a set screw 62 which is positioned preferably near the left end of the spindle 39. The left end of the shaft 61 projects through the left end of the spindle 39 and has a dial 63 secured thereto. The rotor of the condenser is turned by means of the dial 63.

When it is necessary to adjust the spaces between the stator and rotor plates 37 and 38 in order to vary the capacity of the condenser, the differential screw 29 is rotated by applying a wrench to the head 35 thereof. The block 19 is in this manner moved longitudinally in the opening 17 in a proper direction. If the differential screw 29 is moved in an anti-clockwise direction, the block 19 and the stator plates 37 will move to the right. This will increase the distances between the plates 37 and 38 on one side and decrease the distances on the other side. By moving the stator in this manner it is possible to change the capacity of the condenser substantially thirty per cent, if necessary.

The important feature of this means of adjustmentis, in the first place, that the capacity may be varied without touching the rotor and without the necessity of resetting the dial (t3. This is a very important feature because it is sometimes quite a task to reset each dial of a radio.

Another important feature of this arrangement is that it is possible to individually adjust the capacities of the condensers. WVhen a condenser is placed close to a transformer or other radio device, the capacity of the condenser is aifected. In using condensers of my invention it is possible to quickly adjust any condenser relative to the others so that its capacity may be brought to normal with the other condensers.

Although I have shown and described but one form of the invention, it should be understood that slight modifications of design may be made without violating the metes of this invention.

I claim as my invention:

1. A condenser comprising: a rotor having a series of rotor plates; means for rotating said rotor; a stator having a series of stator said stator plates extending between said rotor plates,

block for supporting said stator plates; a

base for supporting said block; and means for moving said stator relative'to said base and said rotor in a manner to vary the distances between said rotor and stator plates, said last named means comprising a screw having a coarse threaded portion and a relatively fine threaded portion, one of which is screwed into said block and the other of which is screwed into said base.

2. A condenser comprising: a rotor having a series of rotor plates: means for rotating said rotor: a stator having a series of stator plates, said stator plates extending between said rotor plates, and said stator having a block for supporting said stator plates; a base for supporting said block; means for moving said stator relative to said base and said rotor in a manner to vary the distances between said rotor and stator plates; and a spring attached to said block and engaging a lower face of said base, resiliently holding said block against said base so that said block may be moved parallel to the plane of said spring.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 1st day of February, 1927.

ROBERT A. PFLEGER. 

